Blueprint is a php web application I made for the online game Eve-Online, a while back i was building and selling ships and i wanted to know how much materials would cost and to be able to find out what my profit was going to be, and this was the result.
There is a working example of this at http://www.xnet.tk/blueprint. This uses php5 and some javascript to redirect users here and there, and its quite primitive from a programming point of view, objects are used for interacting with the database and such, but there is a separate script to add/remove/modify everything, plus header/footer include pages, but it does work, which is good ;)
Also there is input screening, so that php tags or scripts cant be submitted.
Here are the files